1. Field of the Invention
This invention relates to the preparation of poly(arylene ketones).
2. Discussion of the Prior Art
U.S. Pat. No. 3,065,205 to Bonner discloses the preparation of aromatic polyketones by the reaction of aromatic compounds, such as diphenyl ether, with diacid chlorides in the presence of a Friedel-Crafts catalyst. British Pat. No. 971,227 discloses a similar process for making aromatic polyketones.
U.S. Pat. No. 3,441,538 to Marks discloses the preparation of poly(aromatic ketones) using a boron trifluoride/hydrogen fluoride catalyst system. The polymers are prepared from acyl halides, such as 4-phenoxybenzoyl chloride, or from the reaction of diacyl halides, such as terephthaloyl chloride, with difunctional nucleophilic aromatic compounds, such as diphenyl ether. Phosgene is reported to be a suitable diacyl halide. However, in Examples IX and X of that patent where the reactants are phosgene and diphenyl ether, very low yields, 1.5 and 1.1 percent respectively, of low molecular weight polymer were obtained. In Example IX, more than 50% of the diphenyl ether was recovered unreacted.
U.S. Pat. No. 3,953,400 to Dahl discloses crystalline melt processable polymers having the repeating unit ##STR2## and having a mean inherent viscosity within the range of about 0.8 to about 1.65 and an elongation of at least 50%. The polymers are prepared, for example, by polymerization of a monomer such as 4-phenoxybenzoyl chloride or fluoride in the presence of a Friedel-Crafts catalyst and a suitable capping agent. The preferred Friedel-Crafts catalyst is a mixture of hydrogen fluoride and boron trifluoride.